~4Dgifts/src/exampleCode/MP/timer README This subtree demonstrates the use of a high resolution timer of the io3 board on an r4k-based SGI system. The io3 clock is 16 Mhz, 32 bits. Period is ~ 268 seconds. Getitimer has a 100 Hz default resolution. With ftimer(1) and by changing FASTHZ in /usr/sysgen/master.d/kernel it is possible to bring the resolution up to 1800 (Power Series systems), i.e., 555 microseconds. This resolution is too coarse for the purpose of some measurements. Two sub-directories containing contrasting Linpack 100 examples using a regular and the high resolution timers are shown. The Linpack 100 benchmark takes about .07 second to run and thus the use of a higher resolution timer is necessary. Also included is a similar io4 timer for the challenge system. Sample Linpack Output --------------------- regular timer: ./linpackd Please send the results of this run to: Jack J. Dongarra Computer Science Department University of Tennessee Knoxville, Tennessee 37996-1300 Fax: 615-974-8296 Internet: dongarra@cs.utk.edu norm. resid resid machep x(1) x(n) 1.67005097E+00 7.41628980E-14 2.22044605E-16 1.00000000E+00 1.00000000E+00 times are reported for matrices of order 100 dgefa dgesl total mflops unit ratio times for array with leading dimension of 201 6.000E-02 1.000E-02 7.000E-02 9.810E+00 2.039E-01 1.250E+00 6.000E-02 3.576E-09 6.000E-02 1.144E+01 1.748E-01 1.071E+00 7.000E-02 5.364E-09 7.000E-02 9.810E+00 2.039E-01 1.250E+00 6.300E-02 2.000E-03 6.500E-02 1.056E+01 1.893E-01 1.161E+00 times for array with leading dimension of 200 6.000E-02 1.000E-02 7.000E-02 9.810E+00 2.039E-01 1.250E+00 7.000E-02 4.768E-09 7.000E-02 9.810E+00 2.039E-01 1.250E+00 6.000E-02 -4.768E-08 6.000E-02 1.144E+01 1.748E-01 1.071E+00 6.300E-02 2.000E-03 6.500E-02 1.056E+01 1.893E-01 1.161E+00 io3 timer: ./linpackd Please send the results of this run to: Jack J. Dongarra Computer Science Department University of Tennessee Knoxville, Tennessee 37996-1300 Fax: 615-974-8296 Internet: dongarra@cs.utk.edu norm. resid resid machep x(1) x(n) 1.67005097E+00 7.41628980E-14 2.22044605E-16 1.00000000E+00 1.00000000E+00 times are reported for matrices of order 100 dgefa dgesl total mflops unit ratio times for array with leading dimension of 201 6.509E-02 1.980E-03 6.707E-02 1.024E+01 1.954E-01 1.198E+00 6.373E-02 1.869E-03 6.560E-02 1.047E+01 1.911E-01 1.171E+00 6.490E-02 1.885E-03 6.679E-02 1.028E+01 1.945E-01 1.193E+00 6.504E-02 1.855E-03 6.690E-02 1.026E+01 1.949E-01 1.195E+00 times for array with leading dimension of 200 6.682E-02 1.967E-03 6.879E-02 9.982E+00 2.004E-01 1.228E+00 6.324E-02 1.837E-03 6.508E-02 1.055E+01 1.896E-01 1.162E+00 6.415E-02 1.842E-03 6.599E-02 1.041E+01 1.922E-01 1.178E+00 6.440E-02 1.835E-03 6.624E-02 1.037E+01 1.929E-01 1.183E+00
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